Functionalized Hydrogels for Articular Cartilage Tissue Engineering

Articular cartilage (AC) is an avascular and flexible connective tissue located on the bone surface in the diarthrodial joints. AC defects are common in the knees of young and physically active individuals. Because of the lack of suitable tissue-engineered artificial matrices, current therapies for AC defects, espe-cially full-thickness AC defects and osteochondral interfaces, fail to replace or regenerate damaged carti-lage adequately. With rapid research and development advancements in AC tissue engineering (ACTE), functionalized hydrogels have emerged as promising cartilage matrix substitutes because of their favor-able biomechanical properties, water content, swelling ability, cytocompatibility, biodegradability, and lubricating behaviors. They can be rationally designed and conveniently tuned to simulate the extracel-lular matrix of cartilage. This article briefly introduces the composition, structure, and function of AC and its defects, followed by a comprehensive review of the exquisite (bio)design and (bio)fabrication of func-tionalized hydrogels for AC repair. Finally, we summarize the challenges encountered in functionalized hydrogel-based strategies for ACTE both in vivo and in vitro and the future directions for clinical translation.(c) 2022 THE AUTHORS. Published by Elsevier LTD on behalf of Chinese Academy of Engineering and Higher Education Press Limited Company. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Articular cartilage (AC) is a flexible connective tissue located on the bone surface in the joints. AC defects are common in physically active individuals. Functionalized hydrogels have emerged as promising substitutes for damaged cartilage in AC repair due to their favorable properties. This article introduces the composition, structure, and function of AC and its defects, and reviews the design and fabrication of functionalized hydrogels for AC repair.